[UA-EAI] Questions regarding MIME EAI requirements

[John Levine]

On Wed, 15 Dec 2021, Mark Svancarek (CELA) via UA-EAI wrote:

> John we're doing our final cleanup of the document, checking each of the metal scores since our criteria changed during creation.
> EAI Readiness Self-certificaton-guide-updated-9Apri21.docx - Google Docs<https://docs.google.com/document/d/1PopXtNog8nJzdpYQcl1JMyIH2gNYJ4_r/edit>
>
> We are looking at the MUA-MIME stuff and can't recall why we assigned GOLD scores to a few of them.

If your mail includes another message as an attachment, either as a 
one-off or as part of a MIME digest of messages, the attached message is 
normally tagged as a message/rfc822.  But it turns out that the rules for 
message/rfc822 are (skipping over some RFC exigeses) that it conforms to 
RFC822 and its successors, i.e. it's ASCII mail.  If your message has EAI 
addresses, it has to be message/global.  If you want working EAI support, 
you need to handle message/global.  In practice, support for 
message/global is very poor.

MUA.35 and .36 are for an obscure corner case where you are sending an 
attached message to a system that does neither SMTPUTF8 nor 8BITMIME, so 
it has to be encoded as base64 or soemthing.  In practice, everyone 
handles 8BITMIME and that corner case never occurs.  Since it is unlikely 
that a non SMTPUTF8 system would do anything with message/global other 
than say it's a mystery attachment, I'd say just take them out.

Regards,
John Levine, john.levine at standcore.com
Standcore LLC